1. Field of the Invention
The present invention relates to ink used for ink jet and methods for manufacturing a conductive film, an electron-emitting device, an electron source using the electron-emitting device, and an image-forming apparatus using the electron source.
2. Related Background Art
A conventional electron-emitting device is roughly divided into two types such as a thermionic-cathode and a cold-cathode. The cold-cathode includes the field emission type (hereafter referred to as FE type), the metal/insulating-layer/metal type (hereafter referred to as MIM type), and the surface conduction type.
An example of the FE-type electron-emitting device is disclosed in W. P. Dyke and W. W. Dolan, xe2x80x9cField Emission,xe2x80x9d Advance in Electron Physics, 8, 89 (1956) or C. A. Spindt, xe2x80x9cPhysical Properties of thin-film field emission cathodes with molybdenum cones,xe2x80x9d J. Appl. Phys., 47, 5248 (1976).
An example of the MIM-type electron-emitting device is disclosed in C. A. Mead, xe2x80x9cOperation of Tunnel-Emission Devices,xe2x80x9d J. Appl. Phys., 32, 646 (1961).
An example of the surface-conduction-type electron-emitting device is disclosed in M. I. Elinson, Radio Eng. Electron Phys., 10, 1290 (1965).
A surface-conduction-type electron-emitting device uses a phenomenon in which electron emission occurs in a small-area thin film formed on a substrate by supplying current to the film in parallel with the film surface. As the surface-conduction-type electron-emitting device, the following are reported: device using an SnO2 film invented by the above described M. I. Elinson, device using an Au thin film {G. Dittmer: xe2x80x9cThin Solid Films,xe2x80x9d 9, 317 (1972)}, device using an In2O3/SnO2 film, {M. Harwell and C. G. Fonstad: xe2x80x9cIEEE Trans. ED Conf.,xe2x80x9d 519 (1975)}, and device using a carbon thin film {Hisashi Araki et al: Vacuum, Vol. 26, No. 1, p. 22 (1983).
As an example of these surface-conduction-type electron-emitting devices, the Hartwell""s device configuration described above is schematically shown in FIG. 10. In FIG. 10, reference numeral 1 denotes a substrate. Reference numeral 4 denotes a conductive film that is configured by a metal-oxide thin film or the like formed on an H-shaped pattern on which an electron-emitting region 5 is formed through energization process.
FIG. 11A shows a schematic top view of the surface-conduction-type electron-emitting device disclosed in Japanese Patent Application Laid-Open No. 8-264112. FIG. 11B is a schematic sectional view of the device in FIG. 11A. In FIGS. 11A and 11B, reference numeral 1 denotes a substrate, 2 and 3 denote electrodes, 4 denotes a conductive film, 5 denotes an electron-emitting portion, 6 denotes a second gap, 7 denotes a first gap, and 10 denotes a carbon film. A method for manufacturing the device will be described below by referring to FIGS. 12A to 12D. First, electrodes 2 and 3 are formed on a substrate 1 (FIG. 12A). Then, a conductive film 4 for connecting the electrodes 2 and 3 each other is formed (FIG. 12B). Then, the so-called xe2x80x9cenergizationxe2x80x9d for supplying a current is applied to the conductive film 4 to form a second gap 6 (FIG. 12C). Then, a voltage is applied between the electrodes 2 and 3 in an atmosphere containing a carbon compound to form a carbon film 10 and an electron-emitting portion 5 (FIG. 12D).
Then, it is attempted to arrange and form the above described electron-emitting devices on a substrate such as glass or the like and use them as an electron source of a large flat panel display. Thus, at the time of applying a plurality of devices to required electron sources, the uniformity of shapes of conductive films of devices directly influences the uniformity of electron sources.
To manufacture a surface-conduction-type electron-emitting device, a method of forming the conductive film 4 without using the sputtering method or vacuum deposition method is disclosed in Japanese Patent Application Laid-Open No. 8-55560 or the like. As an example of the method, there is a method of obtaining a conductive film by applying a solution containing an organic-metal compound onto a substrate by a spinner and thereafter, patterning the solution into a desired shape and thermally decomposing the organic metal compound. Moreover, Japanese Patent Application Laid-Open Nos. 8-171850, 8-277294, 9-069334, 9-245623, 9-245625, 10-012136, and 10-326559 respectively disclose a manufacturing method of forming a conductive film of a desired shape by supplying droplets of a liquid (ink) containing a conductive-film-forming material onto a substrate by ink jet method and baking the substrate. Moreover, it is disclosed in some of the above described specifications to apply hydrophobic or hydrophilic treatment to the surface of a substrate before supplying a liquid (ink) containing the above described conductive-film-forming material to the substrate.
It is an object of the present invention to provide a high-conservation-stability ink used for an ink jet method for forming a conductive film used for an electron-emitting device or a conductive film used for various types of electronic devices, a method for manufacturing an electron-emitting device having a high electron-emitting characteristic, a method for manufacturing an electron source and a conductive film having a high uniformity and superior in characteristics, and a method for manufacturing an image-forming apparatus having a high uniformity and a high image quality.
Moreover, it is an object of the present invention to provide methods for manufacturing high-yield inexpensive electron-emitting device, electron source, and image-forming apparatus.
The configuration of the present invention made to achieve the above described objects will be described below.
That is, the first aspect of the present invention is an ink for an ink jet, characterized by using a solvent containing nitrogen as a main solvent and comprising a metallic element or a semiconductor element.
The second aspect of the present invention is a method for manufacturing a conductive film, comprising the steps of: preparing a substrate; supplying a liquid containing a metallic element or a semiconductor element onto the substrate; and forming a conductive film by heating the substrate to which the liquid is supplied, wherein the liquid uses a solvent containing nitrogen as a main solvent.
The third aspect of the present invention is a method for manufacturing an electron-emitting device, comprising the steps of: supplying a liquid containing a metallic element or a semiconductor element so as to connect a pair of electrodes arranged on a substrate each other; forming a conductive film by heating the substrate to which the liquid is supplied; and forming an electron-emitting portion by applying a voltage between the pair of electrodes, wherein the liquid uses a solvent containing nitrogen as a main solvent.
The fourth aspect of the present invention is a method for manufacturing an electron-emitting device, comprising the steps of: forming first and second electrodes on a substrate; bringing a solution containing polysiloxane or a solution containing an organic silicon compound and acid into contact with the substrate; supplying a liquid containing a conductive-film-forming material so as to connect the first and second electrodes each other; forming a conductive film by baking the solution supplied onto the substrate; and forming an electron-emitting portion by applying a voltage between the first and second electrodes.
The fifth aspect of the present invention is a method for manufacturing a conductive film, comprising the steps of: preparing a substrate; supplying a solution containing polysiloxane or a solution containing an organic silicon compound and acid onto the substrate; supplying a liquid containing a conductive-film-forming material onto the substrate; and forming a conductive film by baking the solution supplied onto the substrate.
The sixth aspect of the present invention is a method for manufacturing an electron-emitting device, comprising the steps of: forming first and second electrodes on a substrate; controlling a contact angle of the substrate surface to water to 70xc2x0 or more; supplying a liquid containing a conductive-film-forming material so as to connect the first and second electrodes on the substrate each other; forming a conductive film by heating the substrate to which the liquid is supplied; and forming a conductive film portion by applying a voltage between the first and second electrodes.
The seventh aspect of the present invention is a method for manufacturing a conductive film, comprising the steps of: preparing a substrate; controlling a contact angle of the substrate surface from water to 70xc2x0 or more; supplying a liquid containing a conductive-film-forming material onto the substrate; and forming a conductive film by heating the substrate to which the liquid is supplied.